Abstract:
A fluid pressure control device in the form of an inertia-controlled valve unit comprises a bypass passage provided through a stepped piston to directly apply the master cylinder pressure to the wheel brake cylinders; a bypass valve including a valve seat provided within the bypass passage to permit the bypass flow of fluid between the inlet and outlet ports, a valve member axially movable within the bypass passage to co-operate with the valve seat to block the bypass flow, and a spring biasing the valve member toward the inlet port, the bypass valve being closed when a pressure difference between the inlet and outlet ports is below a predetermined value and being opened when the pressure difference exceeds the predetermined value; and an extension rod extended from the valve member toward the inlet port and being engageable with the inner wall of the valve housing to open the bypass valve.
Abstract:
Two parallelly arranged proportioning valve assemblies are installed in a housing. The assemblies have respective plungers which are movable against a common spring to slacken the rise of the hydraulic pressure issued from the assemblies with respect to that of the hydraulic pressure fed in the same. A deceleration sensing valve assembly is also installed in the housing so as to regulate the magnitude of a load applied to the common spring in accordance with the degree of deceleration of the vehicle.
Abstract:
A deceleration detecting type proportioning valve for a vehicle arranged in combination with a deceleration detecting valve. Under a no load or light load condition of the vehicle, when deceleration caused by a braking operation reaches a preset value, a deceleration detecting valve is closed. Following this, the proportioning valve which is by-pass connected to the deceleration detecting valve performs proportioning control to provide a controlled hydraulic brake pressure for each rear wheel cylinder to prevent locking of rear wheels. Under a maximum or heavy load condition, even when the deceleration detecting valve closes, the proportioning valve serves to open the hydraulic brake pressure passage to ensure communication between a master cylinder and the rear wheel cylinder to effect increase in hydraulic brake pressure for the latter to the same degree as front wheel cylinders so that insufficiency in the braking force on the rear wheels can be prevented.
Abstract:
A deceleration sensing type proportioning valve for oppositely distributing front and rear wheel braking forces in a vehicle. A valve seat is arranged to follow the movement of an adjustment piston in such a way as to increase the degree of compression of a control spring before a plunger comes into contact with the valve seat. The piston and the plunger move in the same direction to permit arrangement of a valve body portion of the plunger to be carried by the adjustment piston in an embracing manner for reduction in size of the whole proportioning valve assembly.
Abstract:
A vehicle braking system includes a pressure modulating valve interposed in the pressure fluid line between a master cylinder and the rear wheel brake cylinders. The pressure modulating valve comprises a valve seat fluidly disposed in a valve body intermediate an inlet port of the valve body and an outlet port thereof, an inertia ball capable of seating against the valve seat, and apparatus for increasing the magnitude of the vehicle deceleration at which the inertia ball seats against the valve seat in response to an increase of master cylinder pressure.
Abstract:
The control apparatus comprises a housing having first and second hydraulic pressure chambers formed therein and communicated to each other through a communication passage. The first hydraulic pressure chamber is hydraulically communicated with a master cylinder actuated by a brake pedal of the vehicle, while the second chamber is hydraulically communicated with the rear wheel brake cylinders. A differential piston is axially movably disposed within the housing and having one end portion exposed to the first hydraulic pressure chamber and the other end portion projecting into the second hydraulic pressure chamber. The effective area of the differential piston subjected to the hydraulic pressure is made smaller at the one end portion thereof located in the first pressure chamber than at the other end portion located in the second pressure chamber by forming a sealed air chamber adjacent to the first pressure chamber between the inner wall of the differential piston and a stationary sleeve on which the piston is movably supported. An inertia valve member is disposed in the first hydraulic pressure chamber and adapted to close the communication passage when deceleration of the vehicle attains a predetermined value.
Abstract:
A braking fluid pressure control device comprises a housing fixedly mounted at an inclined angle on a vehicle body frame, a differential piston reciprocable within a stepped bore of the housing and an inertia-controlled valve assembly housed in a fluid chamber in parallel with the stepped bore. In this control device, inlet and outlet ports are arranged in relation to the stepped bore to facilitate air purge from the interior of the device and a bypass passage is further provided within the housing to permit fluid flow from the upper portion of the fluid chamber toward the outlet port when brake fluid is supplied into the device.
Abstract:
In a fluid control valve unit for a crossed piping brake system, a pair of inertia-controlled valves are provided to independently control respective braking fluids supplied to the right and left rear-wheel brake cylinders at a rate of pressure increase lower than the rate of pressure increase in a tandem master cylinder. The control valve unit is further provided therein with a movable stepped spool which is moved to forcibly close one of the inertia-controlled valves when braking fluid cannot be supplied to one of the rear-wheel brake cylinders and a stepped piston which is moved to forcibly close the other inertia-controlled valve when braking fluid cannot be supplied to the other rear-wheel brake cylinder.
Abstract:
In a braking fluid pressure control device, a push rod engages against a blind end of a bore extending inwardly and axially with respect to a plunger. Between the plunger and the push rod, the bore provides clearance increasing from the blind end of the bore toward an open end thereof. The push rod projects from the open end of the bore outside the plunger and engages against a plunger seat slidably fitted in a housing bore. The push rod is biased by a spring which is compressed between the plunger seat and a piston. As a result, a radial force is prevented from acting on the plunger as the plunger is urged by the piston. This avoids damage to an inner wall by the plunger increasing the durability of the control device.